Is there a best practice for making changes to a Zope Product? Specifically I've written a product based off of ZCatalog. In the newest version I have added a few things to the _properties and a new index. I've found that instances of my product that have not made changes to the default properties pick up the new _properties. However if someone had previously added a property or changed the default values the new _properties do not show up. I was thinking it may be best to have an upgrade method that can bring any instance up to date by adding properties, etc. Is there a standard way for doing this? Any experiences on one way being better than another? FYI, We've got about a 40 gig ZODB and searching all of it to find objects to upgrade is about impossible. Thanks, Brian Brinegar Engineering Computer Network Purdue University